K2-138, as it is called, is known to be home to at least five exoplanets. They are orbiting the star K2-138 and it’s thought that there could be more undetected planets within the system.
It was discovered through a citizen science project called Exoplanet Explorers where volunteers from all over the world examine data from NASA’s Kepler space telescope looking for exoplanets. It’s hosted on Zooniverse, an online platform for crowdsourcing research.
“People anywhere can log on and learn what real signals from exoplanets look like, and then look through actual data collected from the Kepler telescope to vote on whether or not to classify a given signal as a transit, or just noise,” said Jessie Christiansen, a Caltech scientist and a founder of the Exoplanet Explorers crowdsourcing project.
Astronomers reviewed the work of the citizen scientists and confirmed their findings.
A Closer Look at the System
Researchers continued to study the system after its discovery. The planets are sub-Neptune meaning they are 1.3 and 3.3 times Earth’s radius, but not as large as Neptune. And there is something very interesting about their orbits. Each planet takes almost 50 percent longer to orbit the star than the next planet further in.
A paper (titled K2-138 system: A Near-Resonant Chain of Five Sub-Neptune Planets Discovered by Citizen Scientists) describing the system has been accepted for publication by The Astronomical Journal.